BRPI0813314B1 - LIGHTING SYSTEM - Google Patents

Abstract

light emitting system, and method for controlling light to provide a desired light-induced physiological stimulus and a desired light stimulus In this document, methods and systems for emitting light that can provide a desired light-induced physiological stimulus and a desired light stimulus are disclosed. . Light can be controlled to vary the physiological stimulus within a first predetermined range while maintaining the light stimulus within a predetermined second range that is useful for a range of self-luminance and space applications. For example, a device may include a controller for controlling the drive currents supplied to a plurality of light emitting elements having different spectral characteristics, characterized in that the combination of currents is controlled such that the mixed emitted light is associated. with the desired physiological and light stimuli.

Description

DESCRIPTION

The invention relates to lighting systems that employ light-emitting elements and, more particularly, to lighting systems configured to provide lighting, as well as to stimulate a desired light-induced physiological effect.

Traditionally, lighting systems have been used only to illuminate, that is, to provide sufficient artificial light that makes it possible to visually recognize characteristics of the environment or, in the case of direct vision systems, the lighting system itself. Relatively recent research illustrates that light can also affect certain physiological functions of life forms and cause a variety of physiological effects, as described, for example, in Figueiro Research Matters, Luzing Design and Application 36 (5), 15-17, 2006; Figueiro et al. Demonstration of additivity failure in human circadian phototransduction, Neuroendocrinology Letters 26 (5), 493-498, 2005; Figueiro et al. Orcadian effectiveness of two polychromatic luzes in suppressing human noctumal melatonin, Neuroscience Letters 406 (3), 293-297, 2006 (collectively designated, Figueiro Publications), all of which are incorporated herein by reference. It has been shown that light can induce variations in, for example, general metabolism and the sleep cycle of a variety of life forms. Light characteristics, such as their quantity, particular spectral compositions, as well as timing and duration of exposure to light, present important indications of the intensity of light-induced physiological effects. These characteristics are often referred to as light-induced physiological stimuli. It is observed, however, that physiological stimuli, in general, may include different indications than

Petition 870190064826, of 10/07/2019, p. 6/12 light. Specific physiological effects that are relevant or indicative of certain biochemical cycles of metabolism and their effects on life forms throughout the day, for example, sleep-wake cycle, cycles of organic activity and the like are often specifically designated as circadian stimuli.

In general, circadian rhythms are physiological and behavioral oscillations that are usually synchronized with the day's natural light and shadow cycle. Disorders of circadian rhythm are inappropriate or unwanted circadian rhythms. These disorders are typically related to sudden and / or extreme changes in the relationship between an organism's exposure to ambient light and its activity. Long-term disruption of rhythms is believed to lead to significant adverse health consequences for peripheral organs outside the brain, particularly in the development or worsening of cardiovascular disease. Timing medical treatment in coordination with the body clock can significantly increase effectiveness and reduce drug toxicity or adverse reactions. For example, properly regulated treatment with angiotensin-converting enzyme inhibitors (ACEi) can reduce nighttime blood pressure and also benefit left ventricular (reverse) remodeling.

Disorders of circadian rhythm are known to be associated with changes in geographic location (jet lag) and night activity (workers in the last shift of work hours). Another common type of circadian rhythm disturbance is seasonal affective disorder (SAD), which is characterized by symptoms, such as depression during the winter season, when the daylight duration is shortened. It has long been known that circadian rhythms in humans and other animals are affected by exposure of the retina to light.

Consequently, several techniques have been developed to treat circadian rhythm disorders by exposing an individual's eyes or tissue to light. Many of these techniques employ lighting sources configured to generate artificial light that closely simulate the intensity and spectrum of natural light and other dynamic light conditions. For example, a conventional device includes a set of light sources of various colors controlled by a computer. The spectral qualities of the light produced by the light sources are measured and provided to the computer, which then adjusts the light sources to generate the desired light conditions.

Another known device employs a plurality of light-emitting diodes (LEDs) at a particular distance from and oriented towards the individual; a portable power source electrically connected to the LEDs; and a controller to change the operation of the LEDs. The device is light and compact enough to comfortably be used by the individual. One or more of these devices are used to emit light to an individual's retinas, to the individual's vascular tissue, or simultaneously to both the retinas and the vascular tissue. For retinal lighting, small LEDs are integrated into the eyeglass frames and positioned to direct light into the individual's eyes. For lighting the vascular tissue, a lens array and LEDs are contained in a case that is attached against the individual's skin.

Also known are light sources configured to adjust or modulate human circadian rhythms and other photodependent body mechanisms. These light sources can generate light, for example, with spectral components having wavelengths distributed throughout the visible spectrum, in order to be captured by the human eye as being substantially white light. The light energy emitted by the source within an anomalous wave band around a wavelength of 460nm can differ significantly from the energy emitted in any other wave band of equivalent width to increase or suppress the modulation of circadian rhythms in humans .

It is generally known to control the ability to alert humans by exposing them to adequate light radiation without substantially influencing the phase of a melatonin cycle. Melatonin is a sleep hormone that can be used to control a human being's alertness. Adequate light radiation being specified by a fraction of melatonin suppressive radiation production (Melatonin Watt / Watt) and light production (lumen / Watt), the fraction of light production and production being adjusted to obtain the desired effect on phase of said cycle. For example, a conventional technique depicts a viewing screen coupled with a color limiting device. A programmable controller changes signals between an electronic device and a viewing screen to decrease or eliminate a signal of a specific color on the screen at specific times. Eliminating or decreasing the blue color on the screen allows normal melatonin production before normal sleep intervals to allow normal sleep cycles.

It is also known to adjust an individual's circadian rhythm in a space by producing a level of variable light intensity in a continuous regime from a light source. The production of light from a source made available to the individual in space is controlled in response to a control signal that varies in a manner corresponding to the solar and lunar altitude of a predetermined geographical location and the passage of time over an interval of selected time of day in a predetermined geographic location.

Many of these approaches, however, focus solely on inducing the desired physiological effect and, therefore, are poorly suited for lighting. For example, Figueiro Publications recognized that visible radiation with short wavelength (for example, blue light) is mainly responsible for synchronizing the body's circadian rhythms and suggested the use of blue light to induce this beneficial effect. Unfortunately, the amount of short wavelength radiation emitted by ordinary white light sources is quite low. Consequently, blue light itself is much more effective in synchronizing the body's circadian rhythms than white light, as shown in Table 1. Using blue light, however, results in inadequate lighting for most visual tasks.

Light source Photopic Lumens / Watt Circadian stimulus / Watt Warm white fluorescent 100 74 Fluorescent daylight 100 157 Incandescent 12 12 Daylight (6500 K) 70 133 Blue LED 15 418

Table 1 - Photopic and Physiological Properties of Common Light Source (Figueiro Publications)

In addition, conventional systems and methods cannot provide a physiological stimulus within a desired range although they also maintain a certain light stimulus within a range that is useful for a range of self-illumination or space applications. Therefore, there is a need for a new method and system to provide illumination and light-induced physiological stimulation that addresses the drawbacks of conventional approaches.

The applicant for this document recognized and noted that it would be advantageous to provide a source of white light whose spectral power distribution can be modified to increase or decrease its circadian stimulus by electric watt as needed. The light source could then be operated to provide energy efficient space and / or auto-illumination in a normal way, and, when desired, be able to stimulate a desired light-induced physiological effect, for example, by providing the maximum amount of blue light to synchronize circadian rhythms of a human being.

Consequently, an object of the invention is to provide a method and system for providing illumination and physiological stimulus. According to one aspect of the invention, a system is provided for emitting light, the light providing a desired light-induced physiological stimulus and a desired light stimulus, the system comprising: a first or more light-emitting elements configured to emit light from a first wavelength range, said first or more light-emitting elements sensitive to a first or more control signals, a second or more light-emitting elements configured to emit a second wavelength range, said second or more light-emitting elements sensitive to a second or more control signals, and a control system operatively coupled to the first or more light-emitting elements and the second or more light-emitting elements, the control system configured to generate the one first or more control signals and said second or more control signals based on the desired light-induced physiological stimulus, the stimulus the desired light, the first wavelength range and the second wavelength range. The variation of the physiological stimulus can include varied emission of light having frequencies between about 420 nm and about 500 nm. In various modalities, the desired light and physiological stimuli do not exceed predetermined limits or fall within predetermined value ranges.

According to another aspect of the invention, a light control method is provided to provide a desired light-induced physiological stimulus and a desired light stimulus, the method comprising the steps of: generating light having a first wavelength range at a first intensity, generate light having a second wavelength range to a second intensity, adjusting the first intensity and the second intensity to generate mixed light having the desired light-induced physiological stimulus and the desired light stimulus.

In the drawings, similar reference characters generally designate the same parts across different views. Also, the drawings are not necessarily to scale, emphasis, on the contrary, is generally given when illustrating the principles of the invention.

Fig. 1 illustrates Stockman's cone fundamentals for color vision.

Fig. 2 illustrates typical opposing process graphics for red-green and blue-yellow chromatic valence, as well as the achromatic response of a standard human observer.

Fig. 3 illustrates a spectrally decomposed physiological stimulus compared to the VA achromatic photopic efficiency curve of the human eye.

Fig. 4 illustrates an architectural block diagram of a system according to an embodiment of the invention.

Fig. 5 illustrates representative average photometric and scotopic statistical achromatic responses commonly accepted by the human eye as a function of wavelength.

Fig. 6 illustrates a portion of a CIE chromaticity diagram showing mixtures of different sets of light-emitting elements to obtain a desired chromaticity.

Fig. 7 illustrates a system for providing illumination and physiological stimulation according to an embodiment of the present invention.

Unless otherwise defined, all technical and scientific terms used in this document have the same meaning commonly known to a person with common knowledge of the technique to which this invention refers. Specifically, the term light-emitting element (LEE) is used to define a device that emits radiation in a region or combination of regions in the electromagnetic spectrum, for example, the visible region, infrared and / or ultraviolet region, when activated by applying a difference potential through it or passing a current through it, for example. Therefore, a light emitting element may have monochromatic, almost monochromatic, polychromatic or broadband spectral emission characteristics. Examples of light-emitting elements include semiconductor, organic or polymer / polymeric LEDs, optically pumped phosphor-coated light-emitting diodes, optically pumped nanocrystal light-emitting diodes, or other similar devices, as would be readily understood by a worker skilled in the art . Additionally, the term light-emitting element is used to define the specific device that emits radiation, for example, an LED array, chip or other such device as will be readily understood by the person with knowledge of the technique, and can be used equally to define a combination of the specific device that emits radiation together with a unique or shared substrate, directing and / or optical output means of the specific device (s), or a housing or package into which the specific device or devices are placed.

The term light stimulus is used in this document to designate one or more aspects of light as visually captured by a human observer. For example, color, brightness, luminance, intensity, luminous flux, chromaticity, correlated color temperature (in English, CCT) and the like can be considered light stimuli, as would be understood by a worker skilled in the art. Although light can visually stimulate different observers in different ways, it is common practice to use standard metrics to assess various light stimuli. A range of light stimuli or indicators thereof, for example, luminous efficacy, luminance, luminous flux, intensity, correlated color temperature (CCT), color conversion rates (in English, “CRI), and chromaticity under conditions or photopic , scotopic or mesopic are known in the art and standardized for several well-defined observation conditions. For example, CCT is typically defined as the temperature of a Planck radiator whose captured color closely resembles that of a given stimulus at the same brightness and under specified viewing conditions.

The term physiological stimulus induced by light or physiological stimulus is used in this document to designate a characteristic of light, such as quantity, certain spectral compositions as well as time and duration of exposure, which can be important indications for the intensity of the physiological effects induced by light . It is observed, however, that physiological stimuli, in general, may include different indications of light. Specific physiological effects that are relevant or indicative of certain biochemical cycles of metabolism and their effects on life forms throughout the day, for example, melatonin metabolism, sleep and wake cycles, cycles of organic activity and the like are often referred to as stimuli circadian.

In its various modalities and implementations, the invention relates to methods and systems for emitting light providing a desired light-induced physiological stimulus and a desired light stimulus. The light can be controlled to vary the physiological stimulus within a first predetermined range while keeping the light stimulus within a second predetermined range that is useful for a range of auto-illumination or space applications. For example, in some embodiments, a controller is provided to control the drive currents applied to a plurality of light-emitting elements having different spectral characteristics, characterized by the fact that the combination of currents is controlled in such a way that the mixed light emitted it is associated with the desired physiological and luminous stimuli.

According to embodiments of the present invention, the system for emitting light that provides physiological stimulus induced by light and light stimulus includes a first or more light-emitting elements, a second or more light-emitting elements and a control system. Said first or more light-emitting elements are configured to emit light of a first wavelength range and are sensitive to a first or more control signals. In addition, said second or more light-emitting elements are configured to emit light of a second wavelength range and are sensitive to a second or more control signals. The control system is operatively coupled to said first or more light-emitting elements and said second or more light-emitting elements, and is configured to generate both the first and the second control signal. For the generation of these control signals, the control system is configured to use information representative of the desired light-induced physiological stimulus and the desired light stimulus, together with information indicative of a first wavelength range and a second wavelength range. wave. The control signals evaluated by the control system can be used to control the first of the light-emitting elements and the second of the light-emitting elements, so that light having a desired light-induced physiological stimulus within a first range and a stimulus desired light within a second band can be generated.

Typically, humans can capture mixed light from multicolored light sources with different spectral power distributions (SPDs) as white light because the color sensors, or cones, in our retina are sensitive within very wide regions and overlapping of the visible spectrum. For example, the "Stockman's cone fundamentals" graph illustrated in fig. 1 shows the spectral sensitivity of different types of eye cone receptors. What is captured as substantially white light can be a highly variable spectral composition. For example, certain continuous broadband spectra, such as those of daylight or even those with distinct spectral peaks, such as light emitted by a range of chromatic light sources with shortband, such as red, green and blue LEEs , can be captured as white light.

The physiological stimuli induced by light can correlate with the amounts of radiation emitted in specific blue and green regions of the visible portion of the electromagnetic spectrum, and are often independent of the amount of radiation in other spectral regions. As skilled technicians would readily observe, humans and some other species can capture color largely due to certain sensitivities in the visual system to differences in radiation intensity at certain different wavelengths. This sensitivity of the visual system is typically known as color opposition and is addressed by Hurvich et al. In An opponent-process theory of color vision, Psychological Review 64: 384-404, 1957, incorporated herein by reference. Fig. 2 illustrates typical opposing process graphics for red-green and blue-yellow chromatic valence, as well as the achromatic response for an ordinary human observer.

It is observed that there is a range of physiological effects known to be sensitive to certain circadian stimuli, and that different stimuli can cause different physiological effects. The physiological effects can include different levels of metabolism of certain types of hormones, including hormones that can affect or control sleep, cell metabolism, immune reactions and the like. An example physiological stimulus efficiency curve is shown in fig. 3 which generally illustrates the sensitivity of melatonin metabolism to wavelength, as discussed by Rea in A Second Kind of Luz, Opto Photonic News, October 2006, pp. 35-39, incorporated herein by reference. This curve peaks at about 440 nm (blue) and has a local minimum of about 570 nm.

It has been observed that two SPDs can have substantially similar lighting effects, but they can give rise to many different physiological effects. For example, different white lights may have similar intensity and correlated color temperature (CCT), although acting substantially differently as physiological stimuli. For example, in one embodiment of the invention a luminaire based on RGB LEE has two blue LEEs with peak wavelengths of about 440 nm and about 480 nm, respectively. Each as well as both blue LEEs can be used to generate white light from a wide range of CCTs when used in combination with red and blue LEEs. Although the photometric intensity captured by the blue LEE with a peak wavelength of 480 nm, however, it is six times that of the blue LEE with a peak wavelength of 440 nm, the circadian stimulus shown in fig. 3 of 480 nm blue light is about 60% of that of 440 nm blue light. Depending on the blue light ratio of 440 nm and 480 nm, the corresponding circadian stimulus, due to a light source system based on multicolored LEE, can be controlled by about an order of magnitude without typically any noticeable change in light stimuli, such as captured intensity, luminous flux or CCT, varying the relative intensities of the blue LEEs with a peak wavelength of 440 nm and 480 nm. It is observed that the same principle applies when combining these blue LEEs with LEEs of other colors, such as warm white, blue and green.

Generally, changing from light of certain first spectra to light of certain second spectra can affect physiological stimuli to a greater extent than if, at all, a desired light stimulus is affected. For example, in one embodiment, the present invention can be used to maintain a suitably high quality white light associated with a predetermined light stimulus, for example, a predetermined intensity, CCT, CRI, or chromaticity, although this can also cause an effect significant physiological effect by varying a respective physiological stimulus.

Fig. 4 illustrates the architecture of a lighting system based on LEE 100 according to various modalities of the present invention. The lighting system includes LEEs 130 of N different colors, a controller 110 and an optical system 120. In many embodiments, the light source includes LEEs 130 of at least two different colors. Any of the LEEs 130 can emit, for example, red, green, blue, amber, magenta, yellow, cyan, white or other colored light or color combination. Optical system 120 is designed to efficiently capture and mix light emitted by multicolored LEEs. System 100 may include an optical sensor system 140 to assess the spectral composition of mixed light. The optional optical sensor system 140 can be operatively coupled to a properly configured controller and the combination used to control the light-emitting elements in an optical feedback manner. The lighting system may also include a user interface 150 to provide certain parameters provided by a user during operation. The lighting system 100 can be used for various applications of space lighting and / or general purpose auto-lighting, such as accessories / luminaires or in display devices such as screens, panels, monitors or projectors.

The present invention also focuses on a method for controlling an LEE-based lighting system, such as one that can generate light having both desired light and physiological stimuli and / or in such a way that the desired light and physiological stimuli do not exceed predetermined limits or fall within predetermined value ranges. The light generated by the LEE-based light source can provide both light and physiological stimuli, either simultaneously or alternatively. In the last case mentioned, for example, the light source can provide the first desired light and physiological stimuli at once while providing either the light or the physiological stimulus at another time. In other words, the light source can be configured to provide only the desired physiological stimulus, which is generally unsuitable for illumination and does not provide the desired light stimulus, as defined above. The light source can also be configured to provide varying levels or varying types of light and / or physiological stimuli. In some embodiments of the invention, this variability is imperceptible to the observer.

Although some metrics exist to reproduce quantitatively physiological / circadian stimuli, refined metrics to quantify circadian stimuli are being developed in the technique. Different metrics can be employed in the present invention through, for example, reconfiguring the controller or selecting suitable LEEs, as would be readily understood by a worker skilled in the art. A range of light stimuli, for example, luminance, luminous flux, intensity, CCT, CRI and chromaticity under conditions or photopic, scotopic or mesopic, are known in the art and standardized for very well-defined observation conditions. Luminous efficacy, the ratio of luminous flux to radiant flux, is also a similarly known, standardized and potentially useful indicator of light stimuli.

In one embodiment, the light emitted by the LEEs can interact with the components of the lighting system. It can be refracted and absorbed at different rates as determined by the refractive index and absorption at different wavelengths. The optical system can be designed to exploit these effects, in order to properly mix the light coming from the different LEEs in a homogeneous and adequate radiation beam, which is suitable for the desired lighting application. The light provided by the optical system, although being approximately a sum or superposition of the light provided by each LEE, can present undesired and practically irrelevant characteristics, possibly undesirable characteristics of the spectral composition of the light emitted due to absorption, refraction, diffusion, chromatic aberration and the like inside the light source system. In one embodiment, the controller can be configured to compensate for unwanted spectral characteristics in order to maintain the desired light and physiological stimuli in the light emitted regardless of whether an open or closed optical cycle is employed to control the light. For example, the controller can compensate for relatively higher amounts of light absorption with short wavelength by the light source system by increasing the light intensity emitted by those LEEs that directly emit or cause generation of that light with short wavelength.

In addition to LEEs of different colors, different types of LEEs can be used in the light source system. For example, the light source system can employ warm white light with long spectrum, for example, low CCT, LEEs in combination with blue and green LEEs with short spectrum. As another example, the light source may employ only red, green and blue LEEs. Properly controlled, LEEs of different color can be used to vary desirably physiological and luminous stimuli, for example, intensity, CCT or chromaticity of mixed light.

The light-emitting elements can be switched on and off quickly. For a wide variety of lighting applications, transients between on-off cycles can be considered almost instantly. As is known, LEEs, therefore, can be effectively controlled in a variety of different ways. For example, the perceived brightness of light emitted by LEE can be controlled by rapidly pulsating the drive current between LEE on-off states. Typical examples of pulsed current control include pulse width modulation (in English, PWM) and pulse code modulation (in English, PCM). A suitable PWM can be used for precise brightness control over a wide dynamic range. Typically, PWM and PCM methods use drive current trains with either a fixed frequency or pulse duration and switching drive currents between zero (OFF) and a fixed finite value (ON), while varying either the duty cycle or the pulse train density. There are a wide range of variations in PWM and PCM methods in which the amplitudes or frequencies of the drive current can be varied, or in which a finite current other than zero OFF can be used. As is known, light flicker from LEEs pulsed quickly enough is typically imperceptible. The respective low frequency limit, also called the critical fusion frequency, is subject to certain conditions of the observer and can vary between different individuals and species. Human beings normally cannot perceive brightness fluctuations above about 100 Hertz. As is also known, the human visual system is less susceptible to certain variations in color / chromaticity than to fluctuations in brightness. LEEs can also be controlled by varying the amplitude of a continuous drive current. Different embodiments of the invention can employ these and other forms of drive current control.

In some embodiments, the controller controls the LEE drive currents for N different colors of LEEs according to a drive current method. It is observed that more than one LEE can be used per color. In one embodiment, with respect to the light emitted by each LEE, the controller can be either a “rear feed” (open optical cycle) or a “feedback” (closed optical cycle) controller. An optical feedback controller typically requires a suitable optical sensor system that is capable of evaluating, at least to a certain extent, the spectral composition of the light emitted. Additionally, in one embodiment, the light source system may comprise one or more temperature or direct voltage sensors to provide information indicating the operating temperature of the LEEs or other operational characteristics, for example, and the controller can be configured as a controller temperature feedback accordingly, regardless of the use of an open or closed optical cycle. The direct voltage of many types of LEEs can be used to accurately assess LEE junction temperature. A range of other forms of temperature sensors could be known to a worker skilled in the art.

In one embodiment, the controller can be configured according to a suitably accurate model of the light source components based on the LEE system to be able to desirably and accurately control the mixed light emitted, at least in part, in an optical cycle manner Open. The model can include parameters such as nominal color and spectral band range of each LEE, temperature deviation and spectral widening of each LEE, junction temperatures for each LEE, and drive current light response functions for each LEE, it's similar. In modes with an optional optical sensor, the controller can be optionally configured according to dynamic characteristics inherent in the drive current response functions vs. luminous flux to assess dynamic drive current control with reduced unwanted side effects and, thus, perform faster and more stable feedback control.

The controller can include a range of components including microprocessors, microcontrollers, CPUs, programmable logic devices, drivers, direct current sources, voltage stabilizers, and the like, to provide pulsed or direct drive currents for LEEs. The controller is also configured to determine drive currents based on light and circadian or physiological stimuli, and it may be able to provide and switch between different operating methods to create the desired stimuli.

In one embodiment, the controller can be operatively coupled to a memory device. For example, the memory device can be integrated into the controller, or it can be a memory device connected to the controller via an appropriate communication link. In another mode, the controller can store the magnitudes of voltage and / or current of drive voltages and / or currents previously determined in the memory device, for subsequent use during equipment operation. The memory device can be configured as an electrically erasable programmable read-only memory (EEPROM), programmable erasable read-only memory (EPROM), non-volatile random access memory (NVRAM), read-only memory (ROM), memory programmable read-only (PROM), flash memory or any other non-volatile data storage memory. The memory can be used to store data and control instructions, for example, program code, software, microcode or firmware, to monitor or control or one or more devices that are coupled to the controller and that can be provided to execute or process by the CPU associated with the controller.

In embodiments of the present invention, the controller can be appropriately configured to determine drive currents for each LEE color, such that the mixed light provides desired light and physiological stimuli, for example, circadian stimuli, in the ways described above. For example, the controller may include a stimulus control module configured to determine, based, for example, on user input or other instructions, whether a physiological stimulus is desired or not and, if so, a desired amount and type of stimulus to be induced by the lighting system. The stimulus control module can also be configured to determine amounts of light of each type to provide the physiological stimulus, while maintaining one or more light stimuli in a desired range, and to appropriately influence the activation currents of the light-emitting elements.

For example, if the stimulus control module determines that substantially no physiological stimulus is desired, the controller can cause the light-emitting elements to be triggered to provide illumination with desired light stimuli, with no particular consideration in providing physiological stimuli. The desired light stimuli, in one mode, can be determined based on the input signal to the controller, for example, coming from user input. If the stimulus control module determines that a particular physiological stimulus is desired, the controller can cause a selected combination of light-emitting elements to be triggered using selected currents to provide the desired stimulus. The light-emitting elements and drive currents can be selected by the stimulus control module in conjunction with the controller, such that the physiological stimulus and one or more desired light stimuli are within a desired predetermined range, if possible, if possible. the desired physiological stimulus and the desired light stimuli cannot be provided due to the limitations of the lighting system, such as the range of light emitted by the light-emitting elements, so the stimulus control module can adjust one or more of the desired physiological stimuli and the desired light stimuli in a predetermined manner until a viable illumination within acceptable ranges for both light stimuli and physiological stimuli can be found. For example, a lower-than-desired level of physiological stimuli can be induced to preserve lighting at a desired level.

In one embodiment, the controller can be configured to output the desired current waveforms directly to the light-emitting elements operatively coupled to it using current drivers integrated into the controller.

In another embodiment, the controller can be configured to send control signals to the current drivers, the control signals configured to induce the current drivers to emit the desired current waveforms to the light emitting elements operatively coupled to it.

A physiological stimulus provided by light from a given spectrum can be evaluated similarly to intensity or chromaticity, adequately transforming the spectrum of light emitted by the light source based on a physiological stimulus model. The spectrally decomposed sensitivity of an example of a physiological stimulus is illustrated in fig. 3. Fig. 5 illustrates representative average photopic and scotopic statistical responses commonly accepted by the human eye as a function of wavelength. These response characteristics can be used to determine the luminous efficacy of light by weighting the spectral distribution of the light of interest with the respective physiological, photopic, mesopic or scotopic response and evaluating the weighted average values, or by, for example, integration or, approximately , by totaling the weighted values at discrete intervals or another method, as qualified technicians would readily observe.

The invention generally takes advantage of one or more empirical physiological stimulus models of certain physiological effects, each using a certain spectral physiological stimulus function. In one embodiment, these functions can be used to assess an expected physiological effect, evaluating the weighted average or another function of the spectral distribution of the light in question. It is observed that determining a physiological stimulus may require information about the intensity of radiation in the visible regions as well as certain almost visible ones in the spectrum of mixed light. It is also observed that the intensity of radiation in some regions of almost visible wavelength may have little or no effect on light stimuli, such as intensity or chromaticity. It is also noted that an instantaneous physiological stimulus may need to be combined with other information, such as timing, duration and intensity, in order to accurately access potential physiological effects.

A spectral distribution of light, such as a radiant spectral distribution of power, can be transformed to provide a measurement of physiological or luminous stimulus in several ways. For example, a scalar value representing a stimulus, such as melatonin metabolism or light flux can be derived mathematically from a radiant spectral distribution of power through weighted integration, weighted totalization, or other operation, as would be understood by a person skilled in the art . As another example, vector value functions representing tristimulus or chromaticity values can be derived similarly by appropriate operation.

In one embodiment, the controller can be configured with a model of the lighting system as well as respective models for light and physiological stimuli for each or more of the predetermined operating modes of the system. The controller can monitor operating system conditions, for example, temperature, device life, amount of ambient light, and use of them in the form of parameters in these models to assess LEE drive currents suitable for generating light with light and physiological stimuli desired. The desired stimuli can be predetermined or, optionally, provided in real time during operation through a user interface.

The relationship between stimuli, operational parameters and drive currents can have highly non-linear characteristics, but can be resolved in approximate and almost sufficient ways using a range of different methods. For example, the controller can employ standard analytical and non-analytical equation solvers, as well as dependent and free, fuzzy logic, neural network models, and the like to solve the equation system that describes the nonlinear characteristics of relationships between stimuli, parameters and drive chains.

As mentioned above, the light source can generally provide the first desired light and physiological stimuli at one time, while providing either the light or physiological stimulus at another time. In other words, the light source can be configured to provide only the desired physiological stimulus, which is generally unsuitable for illumination, and does not provide the desired light stimulus, as defined above. The light source can also be configured to provide varying levels or types of light and / or physiological stimuli.

In one embodiment, a desired light-induced physiological stimulus can be provided continuously at the same time together with a desired light stimulus, such as luminous flux, intensity, color, chromaticity, CRI, and / or CCT. In another modality, the controller is configured to control the LEEs in such a way that the spectral composition is modulated with additional bursts of light of adequate spectral composition to improve the physiological stimulus while minimally affecting the desired average light stimulus over time. Switching can be done in different ways by properly selecting the duration and frequency of bursts. It is observed that, depending on the brightness of the light, the human visual system is generally less perceptive to variations in color or chromaticity than it is to variations in brightness. In a modality, therefore, luminous stimuli indicative of brightness vary within a smaller range than luminous stimuli indicative of color or chromaticity, allowing, in this way, less noticeable variation in illumination.

In one embodiment, the controller is configured to achieve a desired physiological stimulus while maintaining the desired light stimulus at a predetermined level or within a nearby predetermined range at a predetermined level. If this is not possible, different controller modes can be configured to respond differently. For example, the controller can be configured to exceed certain desired light stimulus limits in order to achieve a desired physiological stimulus, or, alternatively, it can inhibit physiological stimuli that cannot be reached without exceeding light stimulus limits. Other answers are possible, as would be readily understood by qualified technicians, for example to exceed limits of different stimulus by different quantity based on a predetermined priority of priority weighting, in order to determine a viable lighting with acceptable levels of each stimulus.

It is also observed that only light of a certain intensity within a specific spectral range can effectively contribute to a certain physiological stimulus. In one embodiment, the bandwidth of spectral sensitivity or weighting characteristics of a physiological stimulus can be important when determining the dominant wavelengths and bands of the LEEs to be employed in the lighting system.

In one modality, deviation from the dominant wavelengths of the LEEs and the widening of the bandwidth of the LEEs under varying operating conditions may require the use of groups of certain chromatic LEEs with similar but different dominant wavelengths, in order to expand the spectrum of the light emitted by a group. This configuration can ensure that variations in intensity in the spectrum of light emitted by the entire group can still cause significant variations in the physiological stimulus, even if the spectrum of one or more LEEs in the group no longer overlap with the respective spectral physiological response function. For example, sufficiently large numbers of properly stored chromatic LEEs provide a suitable nominal dominant wavelength dispersion to desirably extend the spectrum.

Examples 1, 2 and 3 specify sample configurations of LEEs that can be integrated into a lighting system according to the modalities of the present invention. A lighting system would include the necessary components, software, hardware, firmware and the like, in order to properly control these example LEE configurations.

An example light source based on an LEE system employs red, green and blue LEEs that can emit light that provides a higher physiological stimulus than a broadband white light source emitting light from substantially the same photopic light flux. For example, the photopic luminous flux of a light source can be expressed by weighting the radiant flux of the light source at each visible wavelength by the luminous efficacy (as illustrated in Figs. 3 and 5) at that wavelength, and totaling or integrating the results over a predetermined range of visible wavelengths.

Because the luminous flux is determined by totaling or integrating contributions over a wavelength range, two light sources, for example, an LEE-based light source comprising red, green and blue LEEs, and a white light source of broadband, may have substantially the same total luminous flux, but substantially different spectral distributions. Similarly, physiological stimulus can be expressed by weighting the radiant flux of a light source at each visible wavelength by a physiological response function (for example, melatonin metabolism, as illustrated in Fig. 3) and totaling or integrating the results by a predetermined range of wavelengths. Therefore, since the weighting functions for luminous flux or efficacy and physiological response (for example, melatonin metabolism) can differ substantially, it is possible to configure the different spectral power distributions of the two light sources in such a way that the stimuli Physiological differences differ substantially while the luminous flux remains substantially the same.

Another example light source based on a LEE system employs blue LEEs with two or more different nominal dominant wavelengths and one or more green LEEs and one or more white, and is configured in such a way that the physiological stimulus of the emitted light can be changed without varying the luminous efficiency or chromaticity. As described above, a selected first blue LEE can emit a greater proportion of its production at wavelengths giving rise to a visual stimulus than a selected second blue LEE, while green and white LEEs can emit comparatively little of their production in wavelengths giving rise to the visual stimulus. By varying the relative amounts of light emitted for the first and second blue LEEs, the amount of visual stimulus can thus be changed.

At substantially the same time, the amounts of light emitted for the green and white LEEs can be adjusted to retain substantially the same luminous efficacy or chromaticity. For example, to maintain luminous efficacy, if the relative amounts of blue light are adjusted in such a way that the luminous efficacy of the combined blue light decreases, then the amounts of green and white light can be adjusted to emit a corresponding increase in luminous efficacy of the combined green and white light. The increase and decrease in luminous efficacy can be configured to substantially neutralize, thereby maintaining a substantially constant luminous efficacy.

As another example, fig. 6 illustrates a portion of a CIE chromaticity diagram, characterized by the fact that light from a white LEE, a green LEE, and two blue LEEs is combined to generate a resulting light. The chromaticities of the white, green, first blue and second blue LEEs are at the vertices of 610, 620, 630 and 640, respectively. If the resulting chromaticity can be accurately expressed as a convex combination of chromaticities of the individual LEEs, then the dot 650 chromaticity can be achieved using only one of the blue LEEs, as follows. If only the first LEE having 630 chromaticity is used, then the ratio of (intensity) of blue to white light can be a / b, and the combined blue and white light ratio can be c / d. If only the second blue LEE having 640 chromaticity is used, then the ratio of (intensity) of blue to white light can be x / y, and the ratio of combined blue and white light to green light can be c / z. If both blue LEEs are used, the chromaticity at point 650 can be achieved similarly considering an equivalent blue LEE having a chromaticity along the line segment 660, the chromaticity determined by a convex combination of chromaticities 630 and 640, weighted according to intensities of the two blue LEEs.

Depending on the desired light and physiological stimuli, the lighting system can employ many different LEE color combinations, as discussed in detail below.

Yet another example lighting system based on LEE includes green LEEs with two or more different nominal dominant wavelengths and one or more blue LEEs and one or more white, and is configured in such a way that the physiological stimulus of the emitted light can be changed without varying one or more light stimuli. For example, the relative intensities of one or more LEEs can be changed as in Example 2 to vary a physiological stimulus, although the remaining LEEs can be changed in compensation to maintain substantially invariant luminous efficacy or chromaticity.

Another LEE-based example lighting system includes red, green, blue and amber LEEs or red, blue and white green LEES, and is configured in such a way that the physiological stimulus of the emitted light can be changed without varying one or more stimuli luminous. For example, the relative intensities of one or more LEEs can be changed as in Example 2 to vary a physiological stimulus, although the remaining LEEs can be changed in compensation to maintain substantially invariant luminous efficacy or chromaticity.

The LEE-based lighting system can also employ green, blue and warm white LEEs, and is configured in such a way that the physiological stimulus of the emitted light can be changed without varying one or more light stimuli. For example, the relative intensities of one or more LEEs can be changed as in Example 2 to vary a physiological stimulus, although the remaining LEEs can be changed in compensation to maintain substantially invariant luminous efficacy or chromaticity.

In various embodiments of the invention, the luminous flux can be kept substantially fixed, while varying the physiological stimulus as discussed in connection with Examples 2-3. For example, fig. 3 illustrates that stimulation of melatonin metabolism can be increased by increasing the intensity of radiant light between about 400 nm and about 525 nm. However, to maintain a substantially constant luminous flux, the intensity of radiant light between about 525 nm and 650 nm needs to be increased in such a way that the luminous flux, for example, as represented by the total integrated power spectral density weighted by the function of luminance Υ _λ , remains substantially constant, in other words, an increase in light intensity at lower wavelengths can be balanced by a corresponding reduction in light intensity at higher wavelengths, in order to maintain substantially constant light flux . Additionally, it is observed that, with respect to the melatonin metabolization of fig. 3, both actions (increasing intensity with shorter wavelengths and decreasing intensity with longer wavelengths) can increase this physiological stimulus, due to the negative response (inhibition) of melatonin metabolization with higher wavelengths.

Fig. 7 illustrates a system according to a particular embodiment of the present invention, having a stimulus control module 710 directed to control the drive current to produce a desired physiological stimulus while maintaining desired light stimuli. The stimulus control module 710 is operatively coupled to a controller 720, the control module providing drive currents to N light emitting elements 730. Controller 720 accepts input signal from a user interface 735 or other information source , as well as optical feedback 738 from one or more sensors coupled to the light-emitting elements directly or through an optical system (not shown). Input signal from user interface 735 and feedback 738 is provided to stimulus control module 710 in the form of desired physiological stimuli 711, desired light stimuli 712, and operational parameters 714. The input signals to the control module of stimulus 710 can characterize variables in the lighting system system, such as desired lighting characteristics and current capacity of the light emitting elements, due to device heating, aging, ambient lighting, and the like.

The desired stimuli 711 and 712 and operational parameters 714 are provided as input signals to a processor 716, which determines appropriate LEE drive information 718, for example, drive current waveform control, which can induce one or more lighting aspects based on the desired stimuli 711 and 712e in light of operational parameters 714. For example, if it is feasible to provide light in accordance with all the desired stimuli 711 and 712, the trigger information from LEE 718 can result in waveform control of activation current resulting in this light, as long as the operational parameters remain receptive to this activity. If at least one stimulus is not feasible, processor 716 can determine that alternative LEE trigger information 718 is considered acceptable by a predetermined metric. For example, the 716 processor can determine a solution for LEE 718 trigger information that results in selected stimuli being substantially close to or within its desired operating regions, while other selected stimuli may be substantially neglected or removed from their desired operating regions. . As another example, a viable solution for LEE 718 triggering information, considering current operating parameters 714, can be computed by assigning one or more values to one or more selected stimuli and calculating LEE 718 triggering information that substantially minimizes the distance , or otherwise within a predetermined viable distance, from the values to a desired operating region for stimuli in a vector space, such that the solution is within a viable region defined by current operating parameters.

For example, if stimulus control module 710 determines, for example, due to the input signal coming from user interface 735, that a physiological stimulus A (such as inducing melatonin metabolism) is desired at a specific level, in that physiological stimulus A requires light emission in a frequency band around 450 nm, so the stimulus control module can compute trigger information from LEE 718 which results in an increase in light emitted by blue LEEs producing light in this frequency band, the increase according to the specific level of stimulus A. If it is further specified that the luminous flux and chromaticity must be kept within a pre-specified range, then the stimulus control module can compute LEE triggering information 718 that intensifies LEEs by producing light in other frequency ranges to compensate for the change in blue light, as long as a compensating solution viable situation can be found. If a viable solution cannot be found, for example, if intensifying LEEs in other frequency ranges would result in exceeding the operational limits of the LEEs, then the pre-specified operating conditions, for example the stimulus level A or the luminous flux or bands of chromaticity, can be adjusted and a new viable solution is sought.

The processor 716 may include a microprocessor or microcontroller, or for exclusive use by the stimulus control module 710 or shared with the controller. The microprocessor or microcontroller may include components as would be understood by a person skilled in the art, including CPU, memory, input devices, output devices, interrupt control, clock, and the like.

Although several inventive modalities have been described and illustrated in this document, those who have common knowledge in the art will readily envision a variety of other means and / or structures for performing the function and / or obtaining the results and / or one or more of the advantages described in this document. document, and each of these variations and / or modifications is considered to be within the scope of the inventive modalities described in this document. More generally, those skilled in the art will readily note that all parameters, dimensions, materials and configurations described in this document are taken as an example, and that the actual parameters, dimensions, materials and / or configurations will depend on the specific application or applications for which inventive teachings are / are used. Those skilled in the art will recognize, or be able to determine, using no more than routine experimentation, many equivalents for the specific inventive modalities described in this document. It is important, therefore, to understand that the preceding modalities are presented by way of example only and that, within the scope of the attached and equivalent claims thereof, the inventive modalities can be reproduced in a manner other than as specifically described and claimed. The inventive modalities of the present disclosure are addressed to each characteristic, system, article, material, game, and / or individual method described in this document. In addition, any combination of two or more characteristics, systems, articles, materials, games and / or methods, if these characteristics, systems, articles, materials, games and / or methods are not mutually inconsistent, is included within the inventive scope of the present invention.

All definitions, as defined and used in this document, are to be understood as superseding dictionary definitions, definitions in documents incorporated by reference, and / or common meanings of defined terms.

As used in this document, the term about refers to a variation of +/- 10% of the nominal value. It is important to understand that this type of variation is always included in any given value provided in this document, whether or not it is specifically mentioned.

Undefined articles one and one, as used in this document in the report and in the claims, unless otherwise clearly indicated, must be understood to mean at least one. The expression and / or, as used in this document, in the report and in the claims, must be understood to mean one or the other or both of the elements thus conjugated, that is, elements that are present together in some cases and disjunctively present in other cases. Multiple elements listed with “and / or must be interpreted in the same way, that is, one or more of the elements thus conjugated. Other elements may be present optionally different from those elements specifically identified by the expression and / or, regardless of whether they are related or not related to those elements specifically identified. Thus, as a non-limiting example, a reference to A and / or B, when used in conjunction with non-limited language, as comprising may refer, in one embodiment, to only A (optionally including elements other than B) ; in another modality, only B (optionally including elements other than A); in yet another modality, both A and B (optionally including other elements); etc. As used in this document in the report and in the claims, it must either be understood to have the same meaning as and / or as defined above. For example, when separating items in a list, either or or and / or should be interpreted as being inclusive, that is, the inclusion of at least one, but also including more than one, of a variety or list of elements, and, optionally , additional unlisted items. Only terms clearly indicated to the contrary, such as just one of or exactly one of, or, when used in the claims, consisting of, will refer to the inclusion of exactly one element of a variety or list of elements. In general, the term or as used in this document will only be interpreted as indicating exclusive alternatives (ie, one or the other, but not both) when preceded by terms of exclusivity, such as one or the other, one of, only one of, or exactly one of essentially consisting of, when used in the claims, will have its common meaning as used in the field of patent law.

As used in this document in the report and in the claims, the expression at least one, in reference to a list of one or more elements, must be understood as meaning at least one element selected from any one or more of the elements contained in the list of elements, but not necessarily including at least one of each and each element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements other than those specifically identified may be present optionally within the list of elements to which the expression “at least one refers, is related or unrelated to those elements specifically identified. Thus, as a non-limiting example, at least one from A and B (or, equivalently, at least one from A or B, or, equivalently at least one from A and / or B) can refer, in a modality , to at least one, optionally including more than one, A, with no B present (and optionally including elements other than B), in another embodiment, to at least one, optionally including more than one, B, with no A present (and optionally including elements other than A), in yet another embodiment, to at least one, optionally including more than one, A, and at least one, optionally including more than one, B (and optionally including other elements) , etc.

It is also important to understand that, unless otherwise clearly indicated, in any methods claimed in this document that include more than one step or act, the order of the steps or acts of the method is not necessarily limited to the order in which the steps and acts of the method are listed in the claims, as well as in the report above, all transition expressions, such as “comprising, including, carrying, having, containing, involving, maintaining, composed of, and the like must be understood as non-limiting, ie , meaning including, but not limited to. Only transition expressions consisting of and essentially consisting of 5 should be considered expressions with closed or semi-closed meanings, respectively.

The person skilled in the art will understand that the foregoing embodiments of the invention are examples and can vary in many ways. These present or future variations should not be considered as a departure from the spirit and scope of the invention, and all such modifications as would be apparent to a person skilled in the art are intended to be included within the scope of the following claims

Claims (8)

1. SYSTEM (100) FOR EMITTING LIGHT, the light providing a predetermined physiological stimulus induced by light (711) and a predetermined luminous stimulus, the system characterized by comprising: (a) a first or more light-emitting elements (130, 730) configured to emit light of a first wavelength range, said first or more light-emitting elements (130, 730) sensitive to a first or more signals of control, one or more first light-emitting elements comprising a first set of blue-emitting elements and a second set of blue-emitting elements, said first set of blue-emitting elements having a first peak wavelength and said second set of blue light-emitting elements having a second peak wavelength, said first peak wavelength and said second peak wavelength being different; (b) a second or more light-emitting elements (130, 730) comprising at least one green light-emitting element and at least one white light-emitting element, said second or more sensitive light-emitting elements (130, 730) one or more second control signals; and (c) a control system (110, 710) operatively coupled to the first or more light-emitting elements (130, 730) and to the second or more light-emitting elements (130, 730), the control system (110, 710) being configured to vary the physiological stimulus of the light emitted without changing the luminous efficacy or chromaticity, varying the relative amounts of light emitted by the first set of elements emitting blue light and the second set of elements emitting blue light, and varying , at the same time, the quantities of light emitted by at least one element emitting green light and at least one element emitting white light, Petition 870190064826, of 10/07/2019, p. 7/12 in order to maintain the same luminous efficacy or chromaticity. 2. SYSTEM (100), according to claim 1, characterized by the physiological stimulus having one or more physiological effects selected from the group consisting of: hormonal metabolism, sleep control, circadian effects, organic activity, cellular metabolism and immune system response . 3. SYSTEM (100), according to claim 1, characterized in that the light stimulus (712) is selected from the group consisting of: color, brightness, luminance, luminous flux, intensity, color, correlated color temperature and chromaticity. 4. SYSTEM (100), according to claim 1, characterized in that the physiological stimulus (711) includes varying light emission having a wavelength between 420 nm and 500 nm. SYSTEM (100) according to claim 1, characterized in that it further comprises one or more sensors (140) configured to provide one or more feedback signals to the controller (110, 710), wherein said one or more sensors (140) are selected from the group consisting of: temperature sensors, voltage sensors and optical sensors. 6. SYSTEM (100), according to claim 1, characterized by configuring to vary the physiological stimulus (711) in relation to one or more of time, duration and strength to achieve a predetermined effect. 7. SYSTEM, according to claim 1, characterized by being configured to evaluate the physiological stimulus (711) of the light according to one or more empirical physiological stimulus models. 8. SYSTEM, according to claim 7, characterized by the evaluation involving the measurement of a light weighted average spectral distribution over a predetermined range of wavelengths.